The tumours of the endocrine pancreas.

Tumours of the endocrine pancreas are rare entities with evidence of endocrine cell differentiation. Immunohistochemistry is the most reliable method used to study such tumours either for the identification of their hormonal product(s) or to explore functional aspects like proliferative activity or oncoprotein overexpression (e.g. p53). Most of the endocrine tumours of the pancreas are well differentiated and behave as benign or low grade malignant tumours. Poorly differentiated (small cell) endocrine carcinomas are rare and have a poor prognosis.